TRIFIDJE. 165 



first and second transverse lines. The intermediate grey 

 tones of colour seem to prevail northward to a large extent, 

 but a specimen from Sutherlandshire in Mr, W. H. B. 

 Fletcher's collection is. of quite the whitest type, and others 

 from Argyleshire are also white, but almost devoid of 

 markings. 



, On the wing in June and July, and in Scotland continuing 

 into August. 



Larva stout, cylindrical, with the extremities very little 

 smaller; head rounded, red-brown, with a black triangle 

 in front ; body yellowish-grey or brownish- grey ; dorsal line 

 paler, very slender, and enclosed in a necklace-like dorsal 

 stripe which is narrow at the segmental divisions, swelling 

 out on each segment so as to form an angle on each side in 

 the middle of the segment ; at the apex of each angle is a 

 black spot representing the subdorsal line ; this figure is not 

 maintained on the three first body segments, where the stripe 

 is more uniform, but on the third and fourth are two black 

 spots on each side, one in a line with those already denoted, 

 the other in that of the spiracles ; from the fifth onward is 

 an oblique, wedge-shaped, black streak very conspicuously 

 placed in front of each spiracle, which also is black. Legs, 

 prolegs, and undersurface pale grey. When younger, of a 

 light brown or grey-brown colour, the dorsal stripe a series 

 of diamond-shaped marks, the front edges of which are deep 

 black ; lateral oblique streaks black and strongly marked. 



August to April, feeding in the autumn on low plants, 

 such as dock, but after hybernation upon the young shoots 

 of hawthorn, blackthorn, oak, birch, sallow, wild cherry, 

 bramble and other bushes. Feeding at night and hiding 

 itself close to the ground in the daytime. 



Pupa shining brown, with darker wing-covers. Not more 

 particularly described. Subterranean. 



The moth may sometimes be found in the daytime sitting 



